Cyclobenzaprine and Nefazodone interaction
Cyclobenzaprine and Nefazodone: the Cyclobenzaprine prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Cyclobenzaprine (TONMYA) label · effective 2026-08-14
Hyperpyretic crisis seizures and deaths have occurred in patients who received cyclobenzaprine (or structurally similar tricyclic antidepressants) concomitantly with MAO inhibitors drugs.
If serotonin syndrome symptoms occur with the use of other serotonergic drugs, immediately discontinue TONMYA.
Other serotonergic Drugs: Serotonin syndrome has been reported ( 5.2 , 7 )
If concomitant treatment with TONMYA and other serotonergic drugs is clinically warranted, careful observation is advised, particularly during treatment initiation or dosage increases.
Tricyclic Antidepressant-like Adverse Reactions: TCAs have been reported to produce arrhythmias, sinus tachycardia, prolongation of the conduction time leading to myocardial infarction and stroke.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.